--  @testpoint:opengauss关键字nvl(非保留)，作为函数名

--关键字不带引号-合理报错
drop function if exists nvl(i integer);
create function nvl(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
--关键字带双引号-成功
drop function if exists "nvl"(i integer);
create function "nvl"(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
drop function  "nvl"(i integer);
--关键字带单引号-合理报错
drop function if exists 'nvl'(i integer);
create function 'nvl'(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
--关键字带反引号-合理报错
drop function if exists `nvl`(i integer);
create function `nvl`(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
